毛里塔尼亚外海乌贼的繁殖力特性研究

The fecundity of common cuttlefish(Sepia officinalis) in the offshore area of Mauritania

利用2015年7-8月毛里塔尼亚外海渔业生产所得的乌贼(Sepia officinalis)样本,研究该属种的繁殖力特性,并利用数学模型分析个体繁殖力的生物学指标表达关系。结果显示,乌贼个体胴长、体质量等生物学指标均呈单峰型区间分布,个体潜在繁殖力PF为1 306~3 375粒,平均值为2 466±545粒,潜在繁殖力随着性腺发育增加显著(P<0.05);胴长相对繁殖力PF_(ML)为8.70~18.56粒/mm,平均为14.17±2.12粒/mm;体质量相对繁殖力PFBW为2.72~7.81粒/g,平均为5.18±1.23粒/g;PFBW比PF_(ML)更为稳定(δ2PFBW<δ2PFM L)。PF、PFBW均与胴长、胴宽、头宽、鳍长、鳍宽、体质量、净质量和头质量等生物学指标关系密切(P<0.05),PF_(ML)与这些生物学指标的数学模型拟合相关系数较低,函数关系不显著(P>0.05)。多元线性逐步回归分析结果进一步显示,PF与鳍长呈显著的相关关系,而PFBW则与体质量关系显著。研究表明,鳍长和体质量分别是衡量个体潜在繁殖力、体质量相对繁殖力的可靠的生物学指标。

The common cuttlefish, Sepia officinalis Linnaeus 1758, is mostly found in the eastern Atlantic and in the Mediterranean Sea, and constitutes an important fishery resource in the world cephalopod fisheries by attaining high market value in the Mediterranean and Asian markets.Herein,the individual fecundity of S.officinalis was studied based on the samples collected from the pelagic fisheries outside Mauritania during the fishing season of July to August in 2015.In addition, the relationship between individual fecundity and the biological indices of each individual, including mantle length, mantle width, fin length, fin width, head width, body weight, eviscerated weight, and head weight, was analyzed by using mathematic regression equations.The results showed that the frequency distribution of mantle length, mantle width, fin length, fin width, head width, body weight, eviscerated weight, and head weight was unimodal respectively.The potential fecundity （PF） was 13 06~3 375 oocytes, with an average of 2 466＆#177;545 oocytes, and increased significantly with sexual maturation （P〈0.05）;the relative fecundity by mantle length （PFML） was 8.70~18.56 oocytes/mm, with an average of 14.17＆#177;2.12 oocytes/mm;while the relative fecundity by body weight PFBW was 2.72~7.81 oocytes/g, with an average of 5.18＆#177;1.23 oocytes/g.Based on the comparison of variance, PFBW was more stable than PFML （δ2PFBW〈δ2PFM L）.There was a significant relationship between F and PFBW and the biological indices（P〈0.05）, while PFML showed little evidence to correlate with the biological indices due to the low value of correlation coefficient （P〉0.05）.Furthermore, a multiple regression analysis revealed that the potential fecundity was significantly correlated with fin length, while relative fecundity by body weight was significantly correlated with body weight.This finding showed that fin length was the reliable index to estimate the potential fecundity, while body weight was appropriate to estimate the relative fecundity by body weight for S.officinalis.